Carbureter.



W. M. FULTON.

CARBUREIER.

APPLICATION FILED FEB. 4. 1914.

- xtented Nov. 7, 1916.

2 SHEETS-SHEET].

W. M. FULTON.

CARBURETER.

APPLICATION FILED FEB. 4. 1914.

Patented NOV. 7, 1916.

SHEET UNITED STATES PATENT OFFICE.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON CO 015 KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

- CABBUBETER.

Specification of Letters Patent.

Patented Nov. *7, 1916.

Application filed February 4, 1914. Serial No. 816,574.

To all whom it may concern Be it known that I, WESTON M. FULTON, a citizen of the United States, and resident of Knoxville, Tennessee, have invented a new and useful Improvement in Carbureters, which invention is fully set forth in the following specification.

This invention relates to carburetors for internal combustion engines and particularly for engines which operate most efliciently when more or less vacuum is maintained in the manifold.

In liquid fuel explosive engines designed to be used with carbureters in which the air intake to the carbureter is much smaller than the outlet to the engine manifold, a varying degree of vacuum in the manifold and carbureter normally exists. In this type of carbureter there is a liability of the engine taking too great a charge of explosive mixture into the cylinder, resulting in too high compression ignition, particularly if made too large.

The object of this invention is to vary the degree of vacuum in pliance with the demands of the engine an maintain practically a predetermined composition of the air and fuel mixture for delivery to the engine. This I accomplish by placing in the carbureter, between the air inlet and delivery outlet, a thermosensitive device in the path of the incoming air and outgoing air and fuel mixture, adapted to automatically maintain a substantially constant difference of temperature between the incoming air and air and fuel mixture and having connection with the air supply valve, thereby automatically varying the degree of vacuum in the carbureter to the demands of the engine.

In order that the invention may" be readily understood, certain mechanical expressions of the inventive idea are shown in the accompanying drawings, which are designed merely as illustrations to assist the description of the invention, and not as defining the limits thereof, and in which Figure 1 (is a central vertical sectional view, with interior parts in elevation, showing a carbureter provided with my improvements; Figs. 2, 3 and 4 are detail views of parts of the device shown in Fig.1;Fig. 5 is the intake has been to be secured together with possibility of prenot shown, and a the carbureter in comd Which-are secured to the vouter end walls of walls of sections 2 and a vertical central sectional'view showing aslight modification; and .Fig. 6 is a vertical end view of the same.

Referring to Fig. 1, the carbureter casing is formed in three sections 1, 2 and 3 adapted by bolts or other suitable means, and 'in general shape has the form of a U-tube. cludes a liquid fuel reservoir 4 of annular shape surrounding one limb of the U-tube, and delivers fuel through a jet 5 into the path of the air to be carbureted. Fuel is suppliedto the reservoir 4 through a supply pipe 6 controlled by an adjustable valve carried by one arm of a lever 8 pivoted at 9, the opposite arm' of the lever being provided with an annular float 10 for operating the supply valve. mitting access to the valve 7 The upper section 31s provided with a flanged outlet 12 for connecting with the engine manifold, flanged inlet 13' adapted term,

The lower section 1 in- 11 is'a plug for perfor connection with the air induction pipe 14. Sections 2 and- 3 separate on theline A-B, and their walls are provided with bearings 15, 16 for receiving the hubs 17 18 the vibratory vessels 19 and 20. The ends of the hubs are threaded and receive nuts 21, 22 for securing the hubs to their bearings. The opposing walls of the vessels 19 and 20 are each provided with extensions 23, 24 into which is screwed a connecting rod 25 centrally supported in an opening in the 3 and through which Two annular shoulders 26 connecting rod 25, between which is guided a pair of studs 27 (Fig. 2) carried on a link formed in a bellcrank lever arm 28 pivotally supported on a lug 29 on the wall of section 3. Thearm 30 of this lever has a link connection 31 it may play. are formed on the 'with a butterfly damper 32 which is adapted ing wall. Adjustment of the valve 37 is secured by means of a ,rod 40 havinga swivel connection 41 (Fig. 3) with a thumb-screw 4-2 which engages with a threaded opening in the'wall of the section 1. In connection with the spray nozzle or jet 5, and above the same, is located a wire gauze partition 43 forfaciliating breaking up the liquid particles of fuel and facilitating vaporization.

This partition is preferably made so that it may be removed and cleaned, and to this end asemi-annular section is cut out of the wall of the casing for permitting the circular frame of the gauze partitionto be inserted. The frame, as' shown, is carried by a semicircular projection 44 on a semi-annular ring 45 adapted to close the cut-out section in the casing wall, and is provided with bolt holes 46 for fastening the closure to the wall. In Fig. 1, the frame is shown in dotted line position to indicate the manner of inserting or removing it.

' 47 is a throttle valve which is adapted to .be' connected with means under control of an operator, and .48 and-49 are screw plugs for permitting insertion of thermometers when the device is standardized.

Assuming that the parts of the carbureter have been assembled and that the discharge end 12 is connected with an internal combustion engine, the carbureter is to be adjusted in the following manner: Plugs 48 and 49 are removed andthermometers are.

to indicate air and the inserted. One thermometer is the temperature of the incoming other the temperature of the air and fuel .sprayed into the j the wire gauze screen.

liquid and the .into the vaporous state.

vapor mixture. means of thumb-screw 42 for the particular engine to be used and needs no further manipulation. The liquid fuel is admitted to the float chamber 4 from supply pipe (5 a maintained at a proper level by the float 10 acting on the properly adjusted fuel supply valve 7 through its connection 8. The throttle valve 47 is engine is started, thereby causing a draft of air in the direction of the arrows past the spray nozzle 5, through the mixing chamber 50 and to the engine. In normal position, the butterflyvalve 32 is almost closedto restrict the admission of air to a sufficient degree as to cause a partial Vacuum to be formed in the mixing chamber 50 when the throttle valve 47 is nearly closed and the engine is running at lowest speed..' Under these conditions of reduced pressure, fuel is drawn through the nozzle 5 and mixing chamber through The air is thereby the vapor of the volatile temperature 'of the mixture is lowered, owing to the passage of'liquid The two thermometers are thereby subjected to different temperatures while the engine is in operacarbureted by difference of thrust Valve 37 is adjusted by set partly'open and the liquid tion. This difference of temperature between that of the incoming air and the mixture of air and vapor is practically a measure of the ratio of the quantity of vapor to that of the air in the mixing chamber. A. mixture of air and fuel vapor of any predetermined composition may thus be maintained in the mixing chamber by keeping the difference in temperature between the incoming air and outgoing mixture of air and vapor substantially constant. Having fixed upon a predetermined difference of temperature between the incoming air and the outgoing mixture, the: device is adjusted to maintain this difference for different demands on the carbureter. Previous tests with air and gasolene have indicatedthat a about 14 C. between the incoming air and outgoing mixture gives satisfactory results.

While the engine is running, the temperatures are noted on the thermometers. Should this difference be less than the one selected for standardizing the carbureter, the temperature in the carbureter is evidently too high and therefore more fuel needs to be sprayed into the mixing chamber. Thumbscrew 35 is therefore turned in a direction to the lever arm 28 to the left to overcome somewhat the force'exerte'd by the expansion of the vessel 20 upon vessel 19. This moves butterfly damper 32 toward closed position, thereby somewhat reducing the pressure in mixing chamber 50. The increased vaporization of theliquid fuel re duces the temperature of the air and vapor mixture. When the predetermined difference of temperature is reached, the device will maintain this difference, whatever may be the temperature of the incoming air, and therefore maintain constant the composition of the explosive mixture. The thermometers are removed and the plugs 48 and 49 are re- If the throttle valve 47 is now opened to create a greater demand on the carbureter, thereby reducing the pressure inthe carbureter, the amount of liquid drawn into the mixing chamber will increase. The temperature of the air and vapor mixture is lowered in the mixing chamber, while that of the incoming air remains the same. Element 19 will offer less resistance to the expanding force of element 20 and contract, causing butterfly damper to open wider thereby bringing up. the reduced pressure in the mixing chamber and cutting down the fuel supply. This action continues until normal and the predetermined difference of temperature and composition of the mixture is restored.

the proportion of air and vapor again reaches position to maintain the proper thereby moving the damper toward closed supply of chamber.

vapor in the mixing v Owing to the mult plicity of corrugationsin the thermosensitive elements, a slight variation of temperature about either vessel causes an appreciable movement of butterfly damper 32 and quick response to such variation. The composition of the mixture is therefore held between very narrow limits and is practically constant to all variations of the flow of air, and of the. speed of the engine.

That portion of the thermosensitive element ing channel between the same ing chamber 50 are made of sufiicient crosssection relatively to that. of the chamber 50 so that practically the same degree of vac-, uum will always exist around the element 20 as around the element 19, thus preventing air conduit inclosing 20 and the connectany material difference of pressure to act on the two elements.

When the carbureter is provided with means for keeping the temperature of the incoming air constant, the thermosensitive element 19 may obviously be filled with a liquid to prevent effects of pressure variations and vessel 20 in the air intake side then omitted, leaving the element 19 connectedwith the butterfly valve 32.

In adjusting butterfly damper 32 with respect, to thermosensitive elements 19 and 20 when the carbureter is used with automobile engines, the adjustment is such that the vacuum in the carbureter is always sufficient to draw liquid through nozzle 5 at all en- 'ne speeds when the surface of the liquid fuel in the chamber is below the spray nozzle. By this arrangement a lower level of liquid can be kept in the fuel chamber and splashing difficulties largely avoided.

In Figs. 5 and 6, I have illustrated my invention in connection with the puddle type of carbureter in which the air passes over the surface of a puddle of the volatile liquid fuel. The construction and arrangement of the valve operating means is the same as that above described, but the lower section of the carbureter is somewhat modified to form a liquid receptacle 1 closed by a funnel-shaped partition 51 adapted to be supported by its outer screw-threaded rim engaging corresponding threads .on the wall of the section 1. For the purpose of inserting this partition, lugs 52 may be provided for receiving a tool for screwing it in position. The funnel extension or tube 53 extends down into the liquid fuel chamber sufiiciently to insure that the end of the tube always dips below the normal level of the liquid which is maintained practically constant by a float 10 and valve 7, as previously described.

When the engine is-not running, the liquid level rests at the line marked gasolene line."

' amount for and the mix- -said carbureter.

While the engine is running, a certain degree of vacuum is formed above the funnel partition and liquid is drawn up through the funnel tube 53 into the body of the funnel and forms therein a puddle, over the surface of which the air flows in passing through'the carbureter and takes up vapor from the liquid fuel. To facilitate this action, the air is caused to flow in a narrow stratum under a partition 5% which may be extended to quite near the surface of the liquid. Should the amount of vapor absorbed by the air stream be greater than the predetermined which the carbureter is calibrated, the temperature of the air and vapor mixture lowers and causes thermosensitive element 19 to contract, thereby opening butterfly damper 32 wider and relieving the vacuum over the surface of the liquid fuel in the funnel. The liquid level lowers, thus exposing less surfaceto the air and reducing the amount ofvaporization of the fuel. When the vapor in the mixture falls below the predetermined amount,- the reverse of this operation takes place and the liquid rises to expose a greater vaporizing surface.

What is claimed is 1. In a carbureter, a conduit one end of which is for connection with an internal combustion engine, a valve located at the inlet end of the conduit to control the volume of airsupplied to the conduit, means for spraying liquid fuel into the air in the conduit, and a compound thermosensitive device having a connection with said valve and responsive to the temperatures of the incoming airand the outgoing air mixture for operating said valve to proportion the air supply to the varying fuel supply for maintaining a constant composition of the mix-- ture;

2. In a carbureter provided with a valvecontrolled air supply and means for spraying liquid fuel into the air current, thermosensitive means exposed to both the entering air and to the air. and fuel mixture for'operating said inlet valve whereby a constant composition of air and fuel is delivered by 3. In a carbureter, a conduit one end of lilo which is for connection with an internal combustion engine, a valve located at the inlet end of the conduit to control the volume of air supplied to the conduit, means for introducing liquid fuel into the air iii the conduit, and means for effecting the mixture of air and fuel, a compound thermosensitive device having a connection with said valve responsive to the temperature of the incoming air and outgoing air" mixture for operating'said valve to proportion the air supply to the varying fuel supply for.main-' taining a. constant composition of the mixture. i

4. In a carbureter adapted for operation under reduced pressure'in connection with internal combustion engines, the combination of a carbureter chamber wherein the air and fuelvapor are mixed, said chamber 5 having an air inlet, and a valve controlled discharge outlet, a valve in said inlet controlling the air supply and a thermostatic device having one member in the path of the air supply and having a connection with the inlet valve and another member in the path of the mixed air and va'or.

5. In a carbureter, a conduit one'end of which is for connection with an internal combustion engine, a valve located at the inlet end of said conduit to control the volume of air supplied to the conduit, a compound thermosensitive device having a connection with said valve and consisting of connected thermosensitive elements one of which is exposed to the incoming air and the other to the outgoing air mixture, and adjusting means yieldingly connected to, said valve and device for adjusting the carbureter to deliver a predetermined and constant air and fuel mixture.

6. In a carbureter, a 'U-shaped conduit one branch of which receives air and the other delivers a r and fuel mixed, valves 1n both branches, a fuel reservolr supported'on onebranch and having a valve-controlled jet opening into said sensitive elements rigidly connected, one of which is in the inlet branch and the other in the outlet branch, a compound lever connection between the inlet valye and one of said elements, and yielding means for adjusting the position of said valves. 7

In a carbureter adapted for operation under reduced pressure in connection with an internal combustion engine, a casing having an air receiving chamber provided with a valve controlled air inlet and an air and vapor mixing chamber'open to said firstnamed chamber, a compound thermosensitive device one element of which is in the air receiving. chamber and the other element is in the mixing chamber, connections between said device and said valve, a liquid fuel supply nozzle delivering into said mixing chamber under the reduced pressure maintained in the latter,

delivery branch, a com pound thermosensitive devlce having thermoand a hand-operated valve controlling said nozzle. 8. In a carbureter adapted for operation under reduced pressure in connection with an'internal combustion engine, a casing having an air receiving chamber provided with a valve controlled inlet and an air and vapor mixing chamber open to the first chamber and having a discharge outlet, a compound thermosensitlve device having one element in the air receiving chamber and the other element in the mixing chamber, connections charge outlet and opening into the firstnamed chamber, a compound thermosensitive device having a vibratory element in the air receiving chamber and another vibratory element in the mixing chamber, a rigid connection between their movable ends and lever connections between said rigid member and said valve, and means for applying an adjustable yielding pressure to said rigid connection for the purpose described.

10. In a carbureter operated under reduced pressure, a source of fuel supply, a conduit admitting air to the mixing chamber of said carbureter, thermosensitive means in the mixing chamber unresponsive to variations of pressure therein, and devices operatively connected to said thermose'nsitive means to decrease the airsupply passing through said conduit on a rise of temperature in the mixing chamber and to increase said air supply on a lowering of said" temperature, whereby a constant composition of the air and fuel mixture is main tained under varying demands on'the carbureter. I

In-testimony whereof I have signed this specification in the presence of two subscrib- 7 mg witnesses. I

WESTON M. FULTON. Witnesses:

I. A. MARTIN; CQARMISTEAD. 

